The present invention relates generally to improvements in receptacles, enclosures or the like and it relates more particularly to an improved hermetically sealed housing for removably containing in a visually accessible condition, an indicating instrument as well as electrical circuitry associated therewith.
In many environments which are often subject to a wide range of ambient and frequently severe conditions, for example, in the cockpit or other areas of an aircraft or space vehicle, large numbers of information indicating instruments and associated circuit networks are located. Not only must these instruments be easily and rapidly visually accessible but the instruments and associated proximate electrical circuit networks must be completely protected and isolated from the ambient atmosphere but they must be easily physically accessible, removable for inspection, servicing, repair and maintenance and readily replaceable to their original sealed and protected condition. Many structures have been employed and proposed for this purpose but they possess numerous drawbacks and disadvantages. Access to the instruments and associated circuits were awkward, inconvenient and time consuming and the stability and the hermetic seal of the replaced instrument and circuit were frequently defective and unreliable, the structures possessed little versatility and adaptability, were often bulky and otherwise left much to be desired.